We had to provide ID at the Yankee stadium earlier in the year, fortunately we carry our passports around as they are needed quite often when making credit card purchases, although many places are now joining the 21st century and offering chip and pin.
Problem is football attracts more than its fair share of twats, I don't really want to attend a match and get covered in beer just because a couple of twats decide it is funny to throw their beer in the air.
US supporting also isn't as passionate, certainly at baseball, with their organ chants...